Form 1120S is the tax form S corporations use to file their federal income tax return (not to be confused with Form 1120 for C corporations). Every S corp. needs to file one, including LLCs that are taxed as S corps. S corps use this tax form to report any profits, losses, and deductions for that fiscal year.

Note that since S corps are pass-through tax entities––meaning the income “passes through” to the owners––the business income is reported on the shareholders’ personal income tax returns. This simply means that S corps don’t pay corporate taxes; instead, income is taxed at the owners’ personal income tax rate.

Form 1120-S is very crucial for S corps because, in addition to reporting income, it also tells the IRS what percentage of the company is owned by individual shareholders. This will determine any tax payments or refunds that are due to shareholders on their personal income tax returns. Passing tax liability on to a business’s owner is the primary objective for electing to be an S corp., so making sure that this information is accurately reported to the IRS ensures that the business actually secures this benefit.

Information You Will Need to File Form 1120S

Before you rush to fill the form, you’ll need to have the following items handy:

  • Your date of incorporation
  • A list of your products or services
  • Your business activity code
  • Your Employer Identification Number (EIN)
  • The date you elected S corp. status: This will be January 1 if your business operates on a calendar-year basis. It will be on the first day of your fiscal year if you operate on a fiscal-year basis.
  • A profit and loss statement and a balance sheet: You can create these manually or if you use Bench, we’ll create them for you.
  • Your accounting method: You’ll indicate on the form whether you use cash or accrual accounting.
  • Independent contract payments: Any payments to independent contractors totaling at least $600 for the year will need to be reported on the form. You also must provide contractors with 1099 forms.

How to Fill out Form 1120S

Form 1120S is complicated. There are multiple Schedules that you may have to fill out, depending on your situation. Each of these will be covered below.

Step 1: Select

From the Main Menu of TaxSlayer Pro select Business, then 1120S – S-Corporation Return.

Step 2: Enter the EIN of the S Corporation

You will be asked if you want to create a new return. Select YES.

Step 3: Company Information Menu

Here you have to enter the corporation’s Name, Address, and the Date of Incorporation (which is the date the Articles of Incorporation were filed with the state of incorporation). When finished, select OK.

Step 4 – Name & Address Menu

The corporation information that you have entered will be displayed in this menu. Enter the Name, Title, and Contact Phone Number for the Officer of the corporation that is responsible for the filing of the tax return.

This information is required and is expected to be entered in order to electronically file the return. From this menu, you may also enter an optional e-mail address for correspondence from the IRS to the corporation. Exit the menu to be taken to the Heading Information Menu.

Step 5 – Heading Information Menu

  • Total Assets: Enter the Total Assets of the corporation if the entity is not required to complete a Schedule L (as determined by the accounting method regularly used in keeping the corporation’s books and records). If the corporation has assets and gross receipts of at least $250,000, you are required to complete Schedule L and will not enter the Total Assets on this menu. Instead, the Total Assets will be pulled into the return when you complete Schedule L in Step 19 below. If the corporation has no assets at the end of the year, enter ‘0’.
  • Fiscal Year: Enter the Fiscal Year dates only for a corporation that operates on a fiscal year. Most corporations operate on a calendar year, so no entry should be made in this field for any calendar year reporting companies.

Step 6 – Other Information

Note that to electronically file the return, you are expected to enter a valid Business Code and the Date of the S Corp Election. The S Corp Election would have previously been made on Form 2553 and was the corporation’s official notice to the IRS that it was electing to be treated as an S Corporation for tax purposes. Form 2553 should have been filed with the IRS by the 45th day of the tax year in which the election was to be effective.

If the election has not yet been made, see the Instructions for Form 2553 to determine how to proceed and if the entity is eligible for relief from late S Corporation election! If the entity is a Limited Liability Company (LLC), it is expected to file Form 2553 in order to be considered an S Corporation.

After you must have completed this section and if everything is correct, exit the Heading Information Menu and return to the Main Menu of the return (1120S).

Step 7: Schedule B 

From the main menu of the return, select Schedule B – Other Information. You will have to review and answer each of the items found on Schedule B. The answers to questions in this section will control what sections of the return will ultimately need to be completed.

You must the answer the questions regarding the Method of Accounting (Cash, Accrual or Other), Business Activity, and Product or Service. The remaining items will be answered if applicable since the program has a default answer of ‘NO” for most questions.

Pay special attention to #14 Receipts and Assets at year end less than 250,000”, which defaults to ‘NO”. (In 2017 and prior year programs, this question was item #13.) If the corporation’s asset and receipts are less than $250,000 at the end of the tax year, you should change this to ‘YES’ and you will not have to complete Schedule L (Balance Sheet); Schedule M-1 (Reconciliation of Income), and Schedule M-2 (Accumulated Adjustments). Once you have completed this section and if everything is correct, exit the Other Information Menu.

Step 8: Income 

From the main menu of the return (Form 1120S) select Income At this point, you have to enter the appropriate trade or business activity income. Do not report rental income, portfolio income, or other passive income items in this section. These items are distributive items that are allocated directly to the S Corporation’s Shareholders and will be entered later in the return. Once you have entered all activity income, exit the menu.

Step 9: Deductions 

From the main menu of the tax return (Form 1120-S) select Deductions and enter only trade or business activity deductions/expenses. Just like with the Income in Step 8, do not report any rental activity expenses, deductions allocable to portfolio income, or non-deductible expenses in this section.

If you do not have any activity income or expenses, then Lines 1– 21 of the 1120-S will not have any entries on the form when the return is filed. After you must have entered all expenses and deductions related to the activity income, exit the menu.

Step 10: Schedule K 

From the main menu of the tax return (Form 1120-S) Menu, select Schedule K – Distributive Share Items. Select Income (Loss). At this point, enter any income or loss for any Rental Real Estate Activities, as well as any portfolio activities such as Taxable Interest, Dividends, Royalties or Capital Gains that the S Corporation received. After you must have entered all Rental Real Estate and Portfolio income, exit the ‘Income (Loss)’ Menu to return to the Schedule K Menu.

Step 11: From the Schedule K Menu, select Other Deductions

You will have to enter certain deductions associated with the S Corporations that are given special treatment on the Shareholder’s tax return. These types of deductions include Section 179 Expenses, Contributions, Investment Expenses, and Section 59€ (2) expenditures. Next, select Other Deductions and enter any Other Deductions associated with the corporation. Once you have entered all Deduction Items, select exit to return to the Schedule K Menu.

Step 12: Review

From the Schedule K Menu, review the items in the Credits Menu, Foreign Transactions Menu, and the Alternative Minimum Tax Items Menu (which include Depletion and Oil & Gas activities). Note that each of these sections of the Schedule K involves technical items in their respective areas that will be passed through to the individual shareholders on their K-1’s.

Step 13: From the Schedule K Menu, select Items affecting Shareholder Basis 

Have it in mind that the items in this section will impact the basis of the shareholder(s). It is in this section that you will enter tax exempt income and non-deductible expenses. You will also enter as ‘Property Distributions’ any cash distributions and the fair market value of any property that is distributed to the shareholder.

Finally, you will enter any repayment of loans to the corporation from shareholders in this section. Once you have entered all these of items return to the Schedule K Menu.

Step 14: From the Schedule K Menu, select other

Also note that it is in this section that you will enter Investment Income and Investment Expenses which will be distributed to the shareholders. Also enter Dividends paid by the corporation from accumulated earnings and profits. These items will impact the shareholders’ tax return when they calculate the Net Investment Tax, as well as impacting the Shareholder’s basis.

Step 15

At this stage of the return all of the income, deductions and credits for the corporation should have been entered in the return. Next, a K-1 is expected to be entered for each shareholder in the corporation. Note that in the Schedule K Menu, the default setting for #10 – ‘Automatically Distribute Schedule K Information’ is set to YES.

This allows the program to distribute the items previously entered in the tax return to each shareholder’s K-1’s based on the criteria that you will enter in Step 16. If you chose to override this automatic distribution, you will need to select NO and make the input the entries directly in the K-1.

Step 16: Schedule K-1

From the Schedule K Menu, select  Input and select ‘New’.

At this point you will receive a message asking if the shareholder is an individual. If you select ‘YES’ you will be directed to an entry screen that will allow you to enter the Shareholder Information which includes the Social Security Number of the shareholder.

If you selected No, you will receive an entry screen that has the same information except it will require that you enter the EIN of the shareholder. Both screens require you to enter the Taxpayer Identification Number, Name and Address of the Shareholder.

Also note that both screens also require you to enter the Year End Percentage of Ownership, Beginning Percentage of Ownership and the Number of Days the Beginning Percentage of Ownership is applied.

These entries will allow the program to calculate the correct distribution of income, expenses and other distributions to the respective shareholder.

This step should be repeated for each shareholder of the S-Corporation until 100% of the ownership of the corporation has been allocated. The program will prompt you if have not correctly allocated 100% of the ownership interest in the corporation.

Step 17: Schedule K-1 Edit Menu – Review shareholder’s information

Note that any changes to the previously entered information for the partner can be made from this menu. If you want to review or edit any items that are automatically pulled onto the shareholder’s K-1, select Distributive Share Items.

The program automatically distributes the amounts from Schedule K to each shareholder based on the percentages entered in Step 16. After reviewing, and/or editing entries on the K-1, select Exit to return to the Schedule K-1 Edit Menu.

Step 18: Shareholder’s Basis Worksheet 

From the Schedule K-1 Edit Menu select Shareholder’s Basis Worksheet.

Have it in mind that this worksheet is used to track the shareholder’s basis in the corporation. Enter the beginning basis balance for each Shareholder’s basis and/or otherwise make adjustments to the Shareholder’s Basis to reflect capital contributions, shareholder loans to the corporation, etc., that may have occurred during the year.

After you must have made these Worksheet entries, your K-1’s should be complete. Select Exit and return to the Main Menu of the tax return (Form 1120-S).

If in Schedule B at Step 7 you answered YES to the inquiry ‘Receipts and Assets at year end less than 250,000’, you are NOT required to complete Schedule L. Skip Steps 19-22 and proceed directly to Step 23.

You do not have to complete Schedule L, Schedule M-1 and Schedule M-2, and you do not need to open any of these Menus. When these menus are opened, the program will automatically generate certain sections of the Schedules.

If in Schedule B at Step 7 you answered NO to the inquiry ‘Receipts and Assets at year end less than 250,000’, you are required to complete Schedule L – Balance Sheet, and should proceed to Step 19.

Step 19: Schedule L – Balance Sheets 

From the main menu of the 1120-S Menu, select Schedule L – Balance Sheets.

You will have to select each asset corresponding to corporation’s accounting records and enter the appropriate balances in each asset classification. These asset classifications match what the IRS is seeking on the Schedule L.

For any assets that are classified as ‘Other Current’, ‘Other Investment’ or ‘Other Assets’ on the balance sheet, you will create a Supplemental Statement when you make entries in these fields.

Step 20: Liabilities

After you enter the assets for the corporation, enter the liabilities into the balance sheet.

Select Total Liabilities & Capital from the Schedule L Assets Menu.

Note that for any liabilities that are classified as ‘Other Current’ or ‘Other Liabilities’ on the balance sheet, you will create a Supplemental Statement. The program will prompt you to create the Supplemental Statement when you make entries in these fields.

The program will also automatically pull certain equity positions into the balance sheet from the Shareholder Basis Worksheets, as well as any adjustment to retained earnings that have been generated as a result of the income entries on the return.

Any adjusting entries to the Shareholder’s Equity that is not shareholder specific such as Treasury Stock changes will be entered on this screen. However, most equity adjustments would normally be made on the individual Shareholder’s Worksheets found in the Shareholder’s ‘Schedule K-1 Edit Menu’.

In addition, while working in the balance sheet, the program will provide a balance at the bottom of the menu. The ‘Total Liability & Equity’, ‘Total Assets’ and the ‘Difference’ will be displayed to assist in getting the Balance Sheet to balance.

If you have a beginning balance in retained earnings, the balance sheet may be out of balance until you complete Step 22 and reconcile the items that affect retained earnings. Once you have completed this Menu, you should have a balance sheet that is in Balance. Select Exit to return to the Main Menu of the tax return (Form 1120-S).

Step 21: Schedule M-1 – Reconciliation

You are expected to reconcile any differences between the book income (loss) of the corporation to the income (loss) being reported on the tax return. From the main menu of the tax return (Form 1120-S) select Schedule M-1 – Reconciliation.

You will have to enter this menu to generate the Schedule even if no adjustments will be made. Adjust any items that are different from book income (loss) to the income (loss) on the tax return. The program will pull many of these items from other areas of the return.

Note that the most common item that may need adjustment is depreciation which may be different on the company’s books than on the tax return. This is mainly due to the practice of taking bonus depreciation on a tax return but using more conservative practices on the books of the company.

A depreciation adjustment can either increase book income (loss) or decrease book income (loss). Once these entries have been completed, select Exit to return to the Main Menu of the tax return (Form 1120-S).

Step 22: Schedule M-2 

The final schedule that needs to be included on the tax return is Schedule M-2 – Analysis of Accumulated Adjustments Account, Other Adjustments Account, and Shareholder’s Undistributed Taxable Income Previously Taxed.

From the Main Menu of the tax return (Form 1120-S), select Schedule M-2. You should enter this menu to generate the Schedule even if no adjustments will be made. If any Other Additions or Reductions entries are made, the program will prompt you to complete a supplemental statement describing the adjustment.

Step 23: Mark Return Electronic

When all entries have been complete on the tax return, from the Main Menu of the tax return (Form 1120-S), select Mark Return Electronic if you want to e-file the return. If you have failed to enter certain required information the program will prompt you to correct the items before proceeding.

After you must have successfully marked the return for e-file, you will be able to transmit the return from the Electronic Filing Menu which is accessed from the Business Main Menu after exiting the return. To exit the return press enter or select the Exit button.

Step 24: Receipt Menu

Select Exit from the main menu of the tax return. The Receipt Menu displays an overview of the calculated fees.

At this point you have the option to view and edit the invoice or enter a payment. When you exit the receipt menu you will be asked “Are You Ready to Mark the Return Complete?” Answer ‘NO” if the return is not complete. Answer ‘YES” to mark the return complete and exit back to the TaxSlayer Pro Main Menu.


S corporation status is a tax designation granted by the IRS that lets corporations pass their income through to their shareholders. (You might also sometimes hear S corporations referred to as “Subchapter S Corporation,” “Small Business Corporation” or simply “S Corp.).

Form 1120S, U.S. Income Tax Return for an S Corporation is the tax form S corporations (and LLCs filing as S corps) use to file their federal income tax return. However, it is always advisable that you take all the documents needed to file this form, and ask an accountant to help you fill it.